Permeable gas assembly for gas delivery

ABSTRACT

A valve assembly for controlling gas delivery from a higher pressure fluid source to a lower pressure processing tool. The valve assembly includes a valve poppet movingly engageable with a valve seating member and a fluid permeable insert positioned between the valve poppet and the valve seating member that is unexposed to flowing fluid when the valve poppet is in a closed position thereby preventing fluid flow through the valve assembly and providing a diffusional path for transfer of all flowing fluid when the valve poppet is in an open position. The permeable insert can be inserted into the sealable and engageable surface of either the valve seat member or the valve poppet.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/214,165 filed Aug. 29, 2005 in the name of Glenn M. Tom for“PERMEABLE GAS ASSEMBLY FOR GAS DELIVERY,” issued May 13, 2008 as U.S.Pat. No. 7,370,661, which in turn is a continuation-in-part of U.S.patent application Ser. No. 10/314,728 filed Dec. 9, 2002 in the name ofGlenn M. Tom for “PERMEABLE GAS ASSEMBLY FOR GAS DELIVERY,” issued Aug.30, 2005 as U.S. Pat. No. 6,935,354. The disclosures of suchapplications are hereby incorporated herein by reference in theirentireties, for all purposes.

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention relates to a gas valve assembly, and moreparticularly, to a permeable gas valve assembly that controls fluid flowfrom a fluid source to a processing tool.

2. Description of the Related Art

Many industrial processing and manufacturing applications require theuse of highly toxic fluids. The manufacture of semiconductor materialsrepresents one such application wherein the safe storage and handling ofhighly toxic hydridic or halidic gases becomes necessary. Examples ofsuch gases include silane, germane, ammonia, phosphine, arsine, stibine,hydrogen sulfide, hydrogen selenide, hydrogen telluride, and otherhalide compounds. As a result of toxicity and safety considerations,these gases must be carefully stored and handled in the industrialprocess facility. The semiconductor industry in particular relies on thegaseous hydrides of arsine (AsH₃) and phosphine (PH₃) as sources ofarsenic (As) and phosphorus (P) in ion implantation. Ion implantationsystems typically use dilute mixtures of AsH₃ and PH₃ at pressures ashigh as 1500 psig. Due to their extreme toxicity and high vaporpressure, their use, transportation and storage raise significant safetyconcerns for the semiconductor industry.

For example, arsine is an extremely toxic gas that is used by thesemiconductor industry and typically stored in pressurized containers atabout 250 psi. The handling of arsine cylinders in productionenvironments presents a wide variety of hazardous situations. A leak inone 140 gram cylinder of arsine could contaminate the entire volume of a30,000 square foot building with 10 foot high ceilings to the ImmediateDanger to Life and Health (IDLH) level. If the leak were large, suchcontamination could occur in a few minutes, which would mean that formany hours there would be extremely deadly concentrations in the areanear the source of the spill.

Gas pressure regulating valves of the type for delivering gas at arelatively low pressure, have been known and used for many years.However, these valves are subject to leakages of the highly pressurizedgas along valve stems. Unless some provision is made for preventing suchleakage, the build-up of high pressure gas leakage in trapped volumeswithin the valve device can introduce an unintended bias into theregulator and produce distortion of the delivery control. In order tonullify the effect of leakage, some pressure regulating valves resort tothe use of a constantly open atmospheric vent port for releasing gasleakage directly to the atmosphere. Clearly, in the case of inflammatorygas or explosive gases the possible accumulation of released gas in aconfined area becomes a serious health and safety hazard, and an openport is not an option.

In view of the serious potential for injury or death that could resultfrom an unintended release of these fluids, the prior art disclosessystems for preventing such catastrophic release of toxic fluids. U.S.Pat. Nos. 5,704,965; 5,704,967; 5,707,424; and 5,518,528 teach systemsfor storage and dispensing of gases, e.g., hydridic and halidic gases,which operate at ambient temperature by using a pressure reduction todesorb toxic fluids from zeolite, carbon, or other adsorbent materialshaving high storage (sorptive) capacity for these gases. In thesesystems, gas is adsorbed and stored on the physical adsorbent in a fluidstorage and dispensing vessel and is desorbed from the adsorbent anddischarged from the vessel under dispensing conditions. In such systems,the gas can be stored and dispensed at sub-atmospheric pressure levels,typically below about 700 torr. Physical adsorbent-based systems of suchtype are commercially available from ATMI, Inc. (Danbury, Conn.) underthe trademarks SDS and SAGE.

One issue associated with such adsorbent-based fluid storage anddispensing systems relates to the maintenance of high purity of thedispensed gas, since the purity of the gas is reduced if residualabsorbent material that is entrained in the discharging gas.

The development of the above-described adsorbent-based fluid storage anddispensing systems has been motivated by safety and reliability issuesinvolving packages of high-pressure gases in the semiconductor industry,as part of efforts in recent years to significantly increase the safetyof gas packaging.

Another recent development in the field of enhanced safety fluid storageand dispensing systems is the evolution of systems in which fluid iscontained in a vessel having a fluid pressure regulator in the interiorvolume of the vessel. Such arrangement permits fluid to be stored athigh pressures, with the regulator being operative to discharge fluidfrom the vessel only when it sees a downstream pressure that is belowthe set point of the regulator. Such internally disposed regulatorsystems are more fully described in U.S. Pat. Nos. 6,101,816 and6,089,027, and are commercially available from ATMI, Inc. (Danbury,Conn.) under the trademark VAC.

Despite these developments of safer gas packaging, it remains criticalfor gas packages to be fabricated without the occurrence of, orpotential for, fluid leakage, and to minimize adverse effects that mayresult from valve mishandling or valve failure in the use of such gaspackages.

Accordingly, there is a need in the art for a fluid delivery system thatavoids the occurrence of releases of highly pressurized toxic fluid tothe ambient environment of the system, or impairment of the purity ofthe discharged fluid due to the presence of entrained absorbent materialtherein.

It would therefore be a significant advance in the art to provide afluid delivery system that reduces the possibility of accidentalspillage or release of toxic liquid or gases, eliminates the need forsorbents to control the handling, storage and delivery of toxic fluids,and constrains the flow of fluid during normal operation as well asduring any kind of valve mishandling or valve failure.

SUMMARY OF THE INVENTION

The present invention relates to a gas delivery valve device thatprovides a controlled communication from a fluid source through thevalve device to the processing tool.

In one aspect, the present invention relates to a fluid supply apparatusincluding a fluid source and a permeable fluid valve assembly fordelivery of a fluid from the fluid source to a downstream processingtool, wherein the permeable valve assembly includes:

an inlet port for communication with an outlet of a fluid source forflowing fluid from the fluid source; and

a permeable valve device positioned downstream from the fluid sourcecomprising a valve member and a permeable valve seat member,

wherein:

-   -   the valve device is adapted for movement between a sealing        position that blocks fluid flow through the inlet port and an        open position that permits fluid flow through the inlet port and        valve device,    -   the valve member has a first end and a second end and the first        end is positioned in the inlet port,    -   the valve seat member has an abutting first end having an        outflow bore therethrough for acceptance of an extension        attached to at least a section of the second end of the valve        member,    -   the abutting first end of the valve seat member comprises an        insert that is conformingly configured for engagement with the        second end of the valve member and fabricated of a fluid        permeable material for transference of the fluid from the fluid        source through the inlet port and the permeable section of the        valve seat member to the downstream processing tool when the        valve device is in the open position, and    -   the fluid source comprises at least one of (i) a fluid storage        and dispensing vessel holding a storage medium for said fluid,        and (ii) a fluid storage and dispensing vessel having a pressure        actuated fluid flow control assembly interiorly disposed        therein.

In another aspect, the invention relates to a semiconductormanufacturing facility including a fluid supply apparatus as describedabove, and a semiconductor manufacturing tool.

A further aspect of the invention relates to a fluid supply apparatusincluding a higher pressure fluid source and a permeable valve assemblyfor controlling gas delivery from the higher pressure fluid source to alower pressure processing tool, such permeable valve assemblycomprising:

an inlet port for connection to an outlet of the fluid source forflowing fluid from the fluid source;

a valve poppet movingly engageable with a valve seating member, whereinthe valve poppet has a first end and a second end and the first end ispositioned in the inlet port; and

a fluid permeable insert positioned between the second end of the valvepoppet and the valve seating member,

wherein:

the fluid permeable insert is isolated from flowing fluid when the valvepoppet is sealingly engaged with the valve seating member therebypreventing fluid flow through the valve assembly,

the fluid permeable insert provides a diffusional path for transfer ofall flowing fluid from the higher pressure fluid source when the valvepoppet is not sealingly engaged with the valve seating member,

the permeable insert can be inserted into the sealable and engageablesurface of either the valve seat member or the second end of the valvepoppet, and

the higher pressure fluid source includes at least one of (i) a fluidstorage and dispensing vessel holding a storage medium for the fluid,and (ii) a fluid storage and dispensing vessel having a pressureactuated fluid flow control assembly interiorly disposed therein.

Yet another aspect of the invention relates to a fluid supply apparatusincluding a fluid source and a permeable fluid valve assembly fordelivery of a fluid from the fluid source to a downstream processingtool, said permeable fluid valve assembly comprising;

an inlet port for communication with an outlet of a fluid source forflowing fluid from the fluid source; and

a valve device positioned downstream from the fluid source comprising avalve member and a valve seat member,

wherein:

the valve device is adapted for movement between a sealing position thatblocks fluid flow through the inlet port and an open position thatpermits fluid flow through the inlet port and valve device, the valvemember has a first end and a second end, wherein the first end ispositioned in the inlet port,

the valve seat member has an abutting first end having a boretherethrough for acceptance of an extension attached to at least asection of the second end of the valve member,

the extension at the second end of the valve member is fabricated of afluid permeable material for transference of the fluid from the fluidsource through the inlet port, the permeable extension of the valvemember and the outflow bore of the valve seat member to the downstreamprocessing tool when the valve device is in an open position, and

the fluid source comprises at least one of (i) a fluid storage anddispensing vessel holding a storage medium for said fluid, and (ii) afluid storage and dispensing vessel having a pressure actuated fluidflow control assembly interiorly disposed therein.

In another aspect, the invention relates to a fluid supply apparatusincluding a higher pressure fluid source and a permeable valve assemblyfor controlling gas delivery from the higher pressure fluid source to alower pressure processing tool, said permeable valve assembly comprisinga valve poppet movingly engageable with a valve seating member, and afluid permeable insert positioned between the valve poppet and the valveseating member,

wherein:

the fluid permeable insert is isolated from flowing fluid when the valvepoppet is sealingly engaged with the valve seating member therebypreventing fluid flow through the valve assembly,

the fluid permeable insert provides a diffusional path for transfer ofall flowing fluid from the higher pressure fluid source when the valvepoppet is not sealingly engaged with the valve seating member,

the fluid permeable insert comprises a vapor/gas-permeable andliquid-impermeable material and can be inserted into the sealable andengageable surface of either the valve seat member or the valve poppet,and

the higher pressure fluid source comprises at least one of (i) a fluidstorage and dispensing vessel holding a storage medium for said fluid,and (ii) a fluid storage and dispensing vessel having a pressureactuated fluid flow control assembly interiorly disposed therein.

In another aspect, the invention relates to a fluid supply apparatus,comprising:

a fluid source including at least one of (i) a fluid storage anddispensing vessel holding a storage medium for said fluid, and (ii) afluid storage and dispensing vessel having a pressure actuated fluidflow control assembly interiorly disposed therein; and

a flow control valve adapted to control flow of fluid dispensed fromsaid vessel(s), said flow control valve including (i) a valve poppetmovingly engageable with a valve seating member, and (ii) fluidpermeable material that is unexposed to flowing fluid when the valvepoppet is in a closed position thereby preventing fluid flow through thevalve assembly and providing a diffusional path for transfer of flowingfluid when the valve poppet is in an open position.

A still further aspect of the invention relates to a fluid supplyapparatus, comprising:

a fluid source including at least one of (i) a fluid storage anddispensing vessel holding a storage medium for said fluid, and (ii) afluid storage and dispensing vessel having a pressure actuated fluidflow control assembly interiorly disposed therein; and

a flow control valve adapted to control flow of fluid dispensed fromsaid vessel(s), said flow control valve including (i) a valve poppetmovingly engageable with a valve seating member, and (ii) fluidpermeable material that is unexposed to flowing fluid when the valvepoppet is in a closed position thereby preventing fluid flow through thevalve assembly and providing a diffusional path for transfer of flowingfluid when the valve poppet is in an open position.

Another aspect of the invention relates to a method of dispensing fluid,including providing a fluid supply apparatus as described hereinabove,and actuating the valve to the open position to effect dispensing fromsaid fluid source.

In yet another aspect, the invention relates to a method ofmanufacturing a product in a production process utilizing a fluid,including dispensing the fluid from a fluid supply apparatus of the typedescribed hereinabove

An additional aspect of the invention relates to a method of producing afluid source for use in dispensing fluid, such method includingproviding a fluid supply apparatus as variously described hereinabove,and filling the fluid storage and dispensing vessel with fluid.

The above and other aspects and advantages of the invention will becomeapparent from the following more detailed description, taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a permeable valve device of thepresent invention showing the permeable valve seat and valve poppet in aclosed and sealing position.

FIG. 2 is a side elevational view of a permeable valve device of thepresent invention showing the permeable valve seat and valve poppet inan open and discharging mode.

FIG. 3 is a side elevational view of a permeable valve device of thepresent invention showing the permeable valve seat and valve poppet in afilling mode.

FIG. 4 is a side elevational view of another embodiment of the presentinvention showing the valve seat and valve poppet having a permeableextension in a closed and sealing position.

FIGS. 5 and 6 show the valve assembly of FIG. 4 in different stages ofdischarge through the permeable extension of the valve poppet.

FIG. 7 shows the valve assembly of FIG. 4 fully extended in the fillmode for easy and quick filling.

FIGS. 8 and 9 show the permeable valve assembly incorporated into aregulator using a bellows system for expansion and contraction thattranslates movingly engageable movement to the valve assembly.

FIG. 10 is a schematic representation of a semiconductor productmanufacturing facility, including a fluid storage and dispensingapparatus and flow circuitry, incorporating a permeable valve assemblyof the invention, in which the flow circuitry interconnects the fluidstorage and dispensing apparatus with a semiconductor manufacturingtool.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENTTHEREOF

The disclosures of the following U.S. patents and U.S. patentapplications are hereby incorporated herein by reference, in theirentireties, for all purposes: U.S. patent application Ser. No.10/314,728; U.S. Patent Application Publication 2004/0206241; and U.S.Pat. Nos. 5,704,965; 5,704,967; 5,707,424; 5,518,528; 6,101,816; and6,089,027.

In accordance with the present invention, controlled discharge of apressurized fluid, such as a pressurized toxic gas from a fluid sourceis accomplished by diffusing the gas through a permeable section of avalve assembly device.

Referring to FIGS. 1-3, a valve assembly device in accordance with thepresent invention is generally depicted at 10 having a valve member 12(poppet) and a valve seat member 14. Enclosed within the valve seatmember is an insert 16 fabricated of a permeable material for diffusinggas therethrough. Although not shown, a source of fluid under pressureis preferably disposed immediately upstream from the valve assembly.Downstream of the valve assembly is a processing tool (not shown) thatrequires fluid at low pressure. The valve assembly device of the presentinvention controls passage of fluid from the source to the downstreamtool.

Valve member 12 comprises a first end extension 18 which in FIGS. 1-3extends axially outward and is of sufficient length to extend into theinlet port 20, the line that is attached to the fluid source fortransference of the fluid to the valve assembly. The first end extension18 has a smaller cross-sectional dimension relative to the dimension ofthe inlet port to provide sufficient space for movement of thedischarging fluid from the fluid source through the inlet port. On thesecond end of the valve member is a seating or abutting surface 22 thatengages with a corresponding reversely configured surface 24 of thepermeable valve seat member 14. The second end of the valve memberfurther comprises an extension 26 that extends into an outflow bore 28that extends into and traverses through the permeable valve seat member.

FIG. 1 illustrates one embodiment of the permeable valve assembly of thepresent invention wherein the valve poppet member 12 is fully engagedwith the permeable valve seat member 14 to form a sealing junction toprevent fluid flow from the fluid source to the processing tool. Thecontacting surface 24 of the permeable material insert 16 is completelyisolated from the fluid source by the valve member surface 22 andextension 26 both of which are fabricated of an impermeable material

FIG. 2 illustrates the permeable valve assembly in the operatingposition for flow of fluids from the fluid source through the inletport, around the head of the valve member and through the permeableinsert 16 of the valve seat member 14. Preferably, the extension 26 issized to fit within the outflow bore so that all dispensed fluid passesthrough the permeable material. An o-ring may be further included toprovide a movable seal to ensure transference of fluids through only thepermeable insert 16.

FIG. 3 shows the present embodiment in the fill mode. To facilitatequick refilling of the fluid source, the valve member extension 26 isfully extended away from the valve seat member 14. Preferably, theextension 26 is structurally configured to include a smaller dimensionalend 30 that provides a space or gap 32 between the inner surface of theoutflow bore 28 and the narrowed end 30 of valve member extension 26 toprovide for fluid flow and transference of fluid to the fluid source.

FIG. 4 shows another embodiment of the present invention where thepermeable valve assembly 40 comprises a permeable valve member 42 and avalve seat member 44. Permeable valve member 42 comprises a first endextension 46 which in FIGS. 4-7 extends axially outward and is ofsufficient length to extend into the inlet port 48, the line that isattached to the fluid source for transference of the fluid to the valveassembly. The first end extension 46 has a smaller cross-sectionaldimension relative to the dimension of the inlet port to providesufficient space for movement of the discharging fluid from the fluidsource through the inlet port. On the second end of the valve member isa seating or abutting surface 50 that engages with a correspondingreversely configured surface 52 of the valve seat member 44. The secondend of the valve member further comprises a permeable extension 54 thatextends into an outflow bore 56 that traverses through the valve seatmember.

In this embodiment, the permeable extension 54, attached to the valvemember (poppet), provides a diffusible surface for controlledtransference of gases from the upstream fluid source to the downstreamprocessing tool. In FIG. 4, the valve member surface, and the permeableextension 54 are fully engaged with the valve seat member 44 and outflowbore 56 to form a sealing junction to prevent fluid flow from the fluidsource to the processing tool. The permeable extension 54, is completelyisolated from the fluid source by the sealing junction of valve membersurface 50 and valve seat surface 52 both of which are fabricated of animpermeable material

FIGS. 5 and 6 illustrate the permeable valve assembly in the operatingposition for low and higher flow of fluids from the fluid source throughthe inlet port, through a channel 58 around the head of the valve memberand through the permeable wall of permeable extension 54 to the outflowbore 56. Preferably, the permeable extension 54 is sized to fit withinthe outflow bore so that all dispensed fluid passes through thepermeable material to the downstream processing tool.

FIG. 7 shows this embodiment in the fill mode. To facilitate quickrefilling of the fluid source, the permeable valve member extension 54is fully extended away from the valve seat member 44. In the fill mode,the extended member 54 exposes a groove 59 that facilitates easy filingof the fluid source by bypassing the permeable extension 54 and enteringdirectly into inlet port.

The permeable material fabricated into the valve assembly causes aslight drag that controls the high flow of the fluid that is limited bythe pressure and temperature of the fluid and also the permeability ofthe permeable material. This diffusing factor reduces the potential thatpressure spikes will result downstream. Generally any permeable materialthat is vapor/gas permeable and preferably liquid impermeable may beused and formed of a wide variety of potentially useful materials,including, for example, polypropylene, polyvinylidene fluoride,polytetrafluoroethylene, polyfluoroacetate, and silicone. One preferreduseful material comprises polyvinylidene fluoride.

Permeation of gases through polymers is a well-know phenomenon andtabulated permeability values of a wide variety of materials potentiallysuitable for the permeation insert or permeable valve extension may beemployed to design a gas delivery system in accordance with the presentinvention.

In general, the permeation of a gas through a polymeric film isdetermined by the following equation R=P×SA wherein R=permeation rate, Pis the permeation constant for a given polymeric material, at standardtemperature and pressure, and SA is the surface area of the permeationsurface. Thus, it is possible to control the rate of permeation by anumber of techniques, including: changing the temperature, which will inturn change the vapor pressure and diffusion constant across thepermeable wall; changing the thickness of the permeable wall; andmechanically changing the exposed surface area in the diffusion systemby moving the valve member.

The valve assembly of the present invention is applicable for inclusionis various systems, e.g., as shown in FIGS. 8 and 9. The permeable valveassembly can be included in a regulator 60 that include a bellow system66 and an interior chamber 68 that is directly attached to the smalldiameter extension 26. A pressure differential facilitates movement ofthe valve member into or away from the permeable valve seat member 64.In the alternative, the surrounding chamber is directly attached to thevalve seat member which is then move into or away from the valve member.

If the pressure in the chamber 70 is greater than the pre-selectedpressure within the internal volume 68, a diaphragm system attached tothe valve member 62 will contract and the valve member will be urgedtowards the valve seat member 64 to prevent fluid flow through thepermeable material of the valve assembly. Basically the diaphragm 66 iscompressed forcing the valve member 62 to move towards the valve seat tosealingly engage therewith. Once the fluid pressure in chamber 70subsides, the diaphragm system can expand, as shown in FIG. 9, with theconcomitant unseating of the valve member to establish fluid flowthrough the permeable insert in the valve seat member to the outflowport 78, through chamber 70 and on to the processing tool at 80.

FIG. 10 is a schematic representation of a semiconductor productmanufacturing facility, including a fluid storage and dispensingapparatus and flow circuitry, incorporating a permeable valve assemblyof the invention, in which the flow circuitry interconnects the fluidstorage and dispensing apparatus with a semiconductor manufacturingtool.

The fluid storage and dispensing apparatus 110 includes a generallycylindrical vessel 112 adapted to hold fluid, e.g., liquid or gas, at apredetermined pressure. The valve head assembly comprises a flow controlvalve 120 with an actuator 124 being arranged to selectively actuate thevalve and effect discharge of gas from the vessel in line 142.

The valve actuator 124 is controlled by central processor unit 210,which may comprise a computer or microprocessor control apparatus,coupled in controlling relationship with the valve actuator 124 by meansof signal transmission line 212.

The central processor unit 210 may be constructed and arranged toactuate the valve according to a cycle time program. Alternatively, thecentral processor unit 210 may monitor a process condition in thesemiconductor manufacturing facility 200 by means of process conditionsignal transmission line 216 which conveys a signal indicative of agiven process condition to the central processor unit, causing the unitto responsively actuate the valve actuator 124 to a correspondingextent, to modulate the gas flow in line 142 in proportion to the needsof the semiconductor manufacturing facility.

The central processor unit 210 may also receive a signal correlative ofthe temperature of the vessel in signal transmission line 214, which maybe joined to a thermal sensor or embedded thermocouple associated withvessel 112, to compensate the flow of fluid in line 142 in relation tothe temperature of vessel 112.

The semiconductor manufacturing facility 200 may comprise any suitablearrangement of semiconductor process equipment for the production ofsemiconductor materials or devices, or products containing suchmaterials or devices.

For example, the semiconductor manufacturing facility 200 may comprisean ion implantation system, lithotracks, chemical vapor depositionreactor and associated reagent supply and vaporization equipment(including liquid delivery equipment, bubblers, etc.), etch unit,cleaning apparatus, etc.

In one particular embodiment of the present invention, a liquid hydridefluid is maintained under pressure in vessel 112 and gas derivedtherefrom is selectively dispensed in line 142 to the semiconductormanufacturing facility 200 comprising an ion implantation chamber. Thedispensed gas, together with suitable carrier and/or diluent gas(es), issubjected to ionization, and the resulting ion species are implanted ina substrate, e.g., a semiconductor device precursor structure orsubassembly.

The semiconductor manufacturing facility 200 subsequent to use of thedispensed gas, discharges an effluent gas stream in line 202 which maybe flowed to an effluent gas treatment system 204, for treatment anddischarge of final purified effluent in line 206.

The flow control valve 120 in the fluid storage and dispensing apparatus110 of FIG. 10 may be a permeable valve assembly as describedhereinabove, e.g., of any of the types variously shown in FIGS. 1-7, andthe vessel 112 may be adapted in the manner disclosed in U.S. Pat. No.5,518,528 to hold a physical adsorbent medium having fluid sorptivelyretained thereon and desorbable from the adsorbent medium underdispensing conditions, or the vessel 112 may be adapted in the mannerdisclosed in U.S. Patent Application Publication 2004/0206241 to hold afluid in a reversibly reacted state in a reactive liquid having opposingLewis basicity or acidity, or otherwise to hold the fluid in a liquidstorage medium in the vessel from which the fluid can be liberated underdispensing conditions. Thus, the vessels described herein can be anycontainer for materials. Preferably, the vessel comprise asubatmospheric vessel such as those described in U.S. Pat. No.5,518,528; U.S. Pat. No. 5,704,965; U.S. Pat. No. 5,704,967; U.S. Pat.No. 5,935,305; U.S. Pat. No. 6,406,519; U.S. Pat. No. 6,204,180; U.S.Pat. No. 5,837,027; U.S. Pat. No. 6,743,278; U.S. Pat. No. 6,089,027;U.S. Pat. No. 6,101,816; U.S. Pat. No. 6,343,476; U.S. Pat. No.6,660,063; U.S. Pat. No. 6,592,653; U.S. Pat. No. 6,132,492; U.S. Pat.No. 5,851,270; U.S. Pat. No. 5,916,245; U.S. Pat. No. 5,761,910; U.S.Pat. No. 6,083,298; U.S. Pat. No. 6,592,653; and U.S. Pat. No.5,707,424, hereby incorporated herein by reference, in their respectiveentireties. Preferred vessels include SDS® and VAC® delivery vessels(ATMI, Inc.).

As used herein, the term “storage medium” refers to a material disposedin the fluid storage and dispensing vessel, with which the fluid isinteractive so that the fluid can be stored on, in or by such materialor its interaction product, and from which the fluid is disengageablefor dispensing of fluid from the vessel.

In such respect, the “storage medium” may include a sorbent medium suchas a solvent, liquid, semi-solid, or other material having capability asa storage medium. For example, the fluid storage medium may be areversible reactive liquid medium, e.g., an ionic liquid medium, capableof reactive uptake of fluid in a first step, and reactive release ofpreviously taken up fluid in a second step, wherein the first and secondsteps are reverse reactions in relation to one another, and define areversible reaction scheme. According to another embodiment, the vesseluses a liquid absorbent, such as those disclosed in US PatentPublication No. 20040206241, hereby incorporated by reference.

Alternatively, the vessel 112 may comprise an interiorly disposedpressure actuated fluid flow control assembly as more fully described inU.S. Pat. Nos. 6,101,816 and 6,089,027, wherein such pressure actuatedfluid flow control assembly includes a permeable valve assembly inaccordance with the present invention, e.g., a permeable valve assemblyin a regulator as shown and described with reference to FIGS. 8 and 9herein.

As a further variation, the fluid supply with which the permeable valveassembly is used may be of both types, i.e., a physicaladsorbent-containing vessel adapted to sorptively retain fluid on thephysical adsorbent for fluid desorption and dispensing from the vesselunder dispensing conditions, in combination with an interiorregulator-equipped fluid storage and dispensing vessel, with therespective vessels manifolded or otherwise arranged with flow circuitryto supply fluid to a fluid use facility.

Alternatively, the vessel may be a gas generating vessel that generatesgas to be delivered on demand using an electric current, chemicalreaction or any other means.

As a still further alternative the vessel is an ampoule useful forstorage and delivery of low vapor pressure materials (e.g. liquids andsolids) such as those described in U.S. Pat. No. 6,868,869; U.S. Pat.No. 6,740,586; U.S. patent application Ser. No. 10/201,518; U.S. patentapplication Ser. No. 10/858,509; U.S. patent application Ser. No.10/625,179; U.S. patent application Ser. No. 10/028,743; U.S.Provisional Patent Application Ser. No. 60/662,515; and U.S. ProvisionalPatent Application Ser. No. 60/662,396, hereby incorporated herein byreference, in their respective entireties.

As a still further variation of the system shown in FIG. 10, the flowcircuitry can include a permeable valve assembly in line 142, or theFIG. 10 system can otherwise be constructed and arranged to incorporatea permeable valve assembly, to enhance the safety and flow controlcapability of such system.

The permeable valve assembly of the present invention can for example beused in any system that reduces highly-pressurized gas in a cylinder orprocess line to a lower, useable level as the gas passes through anotherpiece of equipment that uses a valve poppet. The system may furtherinclude a bellow system or springs that react to a pressure differentialto open and close the valve poppet.

1. A valve assembly comprising a valve seat member including a seatingsurface and an outlet passage, and a valve device that is translatablebetween a closed position preventing fluid flow through the valveassembly, and an open position allowing fluid flow to the outlet passageof the valve assembly, wherein one of the valve seat member and valvedevice comprises a permeable material through which fluid passes whenthe valve device is translated from the closed position to the openposition.
 2. The valve assembly of claim 1, wherein the permeablematerial constitutes a portion of the valve seat member.
 3. The valveassembly of claim 2, wherein the valve device includes an extension, andwherein the permeable material portion of the valve seat member matablyengages the extension when the valve device is in said closed valveposition.
 4. The valve assembly of claim 1, wherein the valve devicecomprises said permeable material.
 5. The valve assembly of claim 1,wherein said valve seat member and valve device are coaxial with respectto one another.
 6. The valve assembly of claim 1, wherein the valvedevice is coupled to a pressure-actuated assembly for translating thevalve device between said open position and said closed position.
 7. Thevalve assembly of claim 1, wherein the outlet passage communicates withthe seating surface, wherein the permeable material constitutes aportion of the valve seat member and is of annular form circumscribingthe outlet passage, and wherein the valve device is coaxial with thevalve seat member and axially translatable between the closed positionand the open position.
 8. The valve assembly of claim 1, wherein thevalve device includes a portion that comprises the permeable materialand engages the valve seat member in said closed position.
 9. Apressure-actuated regulator for gas delivery, comprising: a valveassembly comprising (i) a valve seat member defining an inlet and anoutlet passage communicating with said inlet, and (ii) a valve devicethat is translatable between a closed position, in engagement with thevalve seat member, preventing fluid flow through the valve assembly andan open position allowing flow of fluid through the outlet passage,wherein one of the valve seat member and valve device comprises apermeable material that permits flow from said inlet through thepermeable material to the outlet passage when the valve device istranslated from the closed position to the open position; and apressure-actuated assembly comprising (i) a chamber adapted for fluiddispensing, (ii) a pressure-responsive diaphragm in said chamber, and(iii) a coupling member interconnecting the pressure-responsivediaphragm and said valve device, wherein the pressure-actuated assemblyis arranged so that pressure in said chamber exterior to saidpressure-responsive diaphragm that is greater than pressure interior tosaid pressure-responsive diaphragm causes the diaphragm to contract sothat said coupling member translates the valve device to said closedposition, and pressure in said chamber exterior to saidpressure-responsive diaphragm that is less than pressure interior tosaid pressure-responsive diaphragm causes the diaphragm to expand sothat said coupling member translates the valve device to said openposition.
 10. The pressure-actuated regulator of claim 9, wherein thepermeable material constitutes a portion of the valve seat member. 11.The pressure-actuated regulator of claim 9, wherein the permeablematerial constitutes a portion of the valve device.
 12. A fluid storageand dispensing apparatus, comprising: a fluid storage and dispensingvessel; and a pressure-actuated regulator according to claim 9, whereinthe valve assembly is in the vessel.
 13. The fluid storage anddispensing apparatus of claim 12, wherein the chamber of saidpressure-actuated assembly is coupled in fluid dispensing relationshipto a processing tool.
 14. The fluid storage and dispensing apparatus ofclaim 12, wherein the permeable material constitutes a portion of thevalve seat member.
 15. The fluid storage and dispensing apparatus ofclaim 12, wherein the permeable material constitutes a portion of thevalve device.
 16. The fluid storage and dispensing apparatus of claim12, wherein said permeable material comprises material selected from thegroup consisting of polypropylene, polyvinylidene fluoride,polytetrafluoroethylene, polyfluoroacetate and silicone.
 17. The fluidstorage and dispensing apparatus of claim 12, wherein said vesselcontains a semiconductor manufacturing fluid.
 18. A method of deliveringa fluid from a fluid source containing same to a dispensing locus, saidmethod comprising: confining said fluid in said fluid source with avalve assembly comprising a valve seat member including an inlet, aseating surface and an outlet passage, and a valve device that istranslatable between a closed position, in engagement with the valveseat member, and an open position allowing flow of fluid to the outletpassage, wherein one of the valve seat member and valve device comprisesa permeable material that permits flow from said inlet through thepermeable material to the outlet passage when the valve device istranslated from the closed position to the open position; translatingsaid valve device to said open position when pressure at said dispensinglocus falls below a preselected pressure, so that fluid flows from saidfluid source through said permeable material and outlet passage of saidvalve assembly to said dispensing locus; and translating said valvedevice to said closed position when pressure at said dispensing locusrises above said preselected pressure.
 19. The method of claim 18,wherein the permeable material constitutes a portion of the valve seatmember.
 20. The method of claim 18, wherein the permeable materialconstitutes a portion of the valve device.